Systems and methods for dry powder coating layers of an electrochemical cell

ABSTRACT

A system for forming a particle layer on a substrate may include at least one sprayer and at least two masks configured to selectively mask a substrate in a first region and second region of the substrate. The at least one sprayer may be configured to spray particles at the substrate, where the at least two masks maintain the first region and second region substantially free of the deposited material. A heater may be employed to heat the substrate as the particles are sprayed by the at least one sprayer onto the substrate.

RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119(e)to U.S. Provisional Application Ser. No. 62/848,849, filed May 16, 2019,the disclosure of which is incorporated herein by reference in itsentirety.

FIELD

Disclosed embodiments are related to systems and methods for dry powdercoating layers of an electrochemical cell.

BACKGROUND

Lithium ion batteries typically include two or more electrodes separatedby an electrically insulating material that is permeable to thediffusion of lithium ions between the electrodes. In some instances, oneelectrode includes an anode material coated onto a copper substrate andthe other includes a cathode material coated onto an aluminum substrate.The production of these electrodes is conventionally done using slurrymethods, in which the electrochemical materials (e.g. the anode orcathode material) are mixed with a polymer binder (e.g. typicallypolyvinylidene fluoride PVDF) which is dissolved in an appropriatesolvent (e.g. typically N-methyl pyrrolidone). The resulting slurry iscoated onto the electrode substrate. Subsequently, the solvent isevaporated and reclaimed to form a dried layer of electrochemicalmaterial on the electrode surface. In order to remove all of the solventfrom the electrodes prior to assembly into a battery, enormous amountsof time and energy are expended in the use of large conveyor ovens andvacuum dryers that help to dry the deposited slurry.

SUMMARY

In some embodiments, a system for forming a particle layer includes atleast one sprayer configured to spray particles towards a substrate, theparticles including at least one selected from the group of anelectrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material. The systemalso includes a first mask movable to selectively mask the substratefrom the particles in a first region of the substrate, and a second maskmovable to selectively mask the substrate from the particles in a secondregion of the substrate, where the at least one sprayer directs thespray of particles towards a portion of the substrate between the firstmask and the second mask. The system also includes a heater configuredto heat the substrate.

In some embodiments, a method for depositing material layers includesmasking a first region of a substrate, masking a second region of thesubstrate, heating the substrate, and spraying first particlescomprising at least one selected from the group of an electrochemicalmaterial, an ionically conductive material, an electrically conductivematerial, and a separator material towards the heated substrate to forma first layer on the substrate.

In some embodiments, a method of forming an electrode includes masking afirst region of a substrate to inhibit material deposition on thesubstrate in the first region, masking a second region of the substrateto inhibit material deposition in the second region, applying firstparticles comprising at least one selected from the group of anelectrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material to thesubstrate to form a first layer, and applying second particlescomprising at least one selected from the group of the electrochemicalmaterial, the ionically conductive material, the electrically conductivematerial, and the separator material to the first layer to form a secondlayer disposed on the first layer.

It should be appreciated that the foregoing concepts, and additionalconcepts discussed below, may be arranged in any suitable combination,as the present disclosure is not limited in this respect. Further, otheradvantages and novel features of the present disclosure will becomeapparent from the following detailed description of various non-limitingembodiments when considered in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. In thedrawings, each identical or nearly identical component that isillustrated in various figures may be represented by a like numeral. Forpurposes of clarity, not every component may be labeled in everydrawing. In the drawings:

FIG. 1 is a side schematic representation of one embodiment of a spraydeposition system;

FIG. 2 is a side schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 3 is a side schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 4 is a side schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 5 is a top schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 6 is a top schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 7 is a top schematic representation of the spray deposition systemof FIG. 1 during a material deposition process;

FIG. 8 is a top schematic representation of a material produced by thespray deposition system of FIG. 1;

FIG. 9 is a side schematic representation of the material of FIG. 8;

FIG. 10 is a side schematic representation of another embodiment of aspray deposition system;

FIG. 11 is a side schematic representation of the spray depositionsystem of FIG. 10 during a material deposition process;

FIG. 12 is a side schematic representation of the spray depositionsystem of FIG. 10 during a material deposition process;

FIG. 13 is a side schematic representation of the spray depositionsystem of FIG. 10 during a material deposition process;

FIG. 14 is a top schematic representation of a material produced by thespray deposition system of FIG. 10;

FIG. 15 is a side schematic representation of the material of FIG. 14;

FIG. 16 is a top schematic representation of one embodiment of amaterial produced by a spray deposition system;

FIG. 17 is a side schematic representation of the material of FIG. 16;

FIG. 18 is a side schematic representation of yet another embodiment ofa spray deposition system during a material deposition process;

FIG. 19 is a side schematic representation of the spray depositionsystem of FIG. 18 during a material deposition process;

FIG. 20 is a side schematic representation of the spray depositionsystem of FIG. 18 during a material deposition process;

FIG. 21 is a side schematic representation of the spray depositionsystem of FIG. 18 during a material deposition process;

FIG. 22 is a top schematic representation of yet another embodiment of aspray deposition system during a material deposition process;

FIG. 23 is a side schematic representation of yet another embodiment ofa spray deposition system during a material deposition process; and

FIG. 24 is a side schematic representation of yet another embodiment ofa spray deposition system during a material deposition process.

DETAILED DESCRIPTION

The inventors have recognized that prior processes for dry powdermanufacturing of electrochemical cells have produced continuous lengthsof coated material. Specifically, as these processes are performedeither continuously or semi-continuously, a uniform coating without gapsis formed on the substrate using these methods. Therefore, formingsuitable locations for attaching electrical leads to the currentcollectors during a battery cell manufacturing process may involveremoving some of the deposited material prior to a calendering process.Further, in instances where these processes have used resistively heatedsubstrates, the current passes into and out of the substrate through abare portion of the substrate and a corresponding coated portion of thesubstrate which may increase the overall resistance, and thus energyconsumption for a battery layer formation process.

In view of the above, the Inventors have recognized the benefits of asystem for forming a one or more layers deposited onto a substrate, suchas a current collector, of an electrochemical cell in which two or moremasks may selectively cover at least a first region and second region ofthe substrate while a desired material is sprayed, or otherwise applied,on to the substrate to form a layer on the substrate on either one ortwo opposing surfaces of the substrate (e.g., an electrode layer, aseparator layer, a solid state electrolyte layer, etc.). The two or moremasks may prevent the first region and second region from being coatedby the sprayed material such that the first region and second region aremaintained as bare regions of the substrate after deposition of one ormore layers thereon. Depending on whether the deposited layers areapplied to one or two opposing sides of a substrate, these masks, andthe corresponding masked bare regions of the substrate, may be locatedon one or two opposing surfaces of the substrate. In some embodiments,the bare regions may be used to denote regions where an otherwisecontinuous roll of substrate may be separated to form individualelectrodes. The bare regions may also be used to weld electrical leadsto current collectors during a subsequent battery formation process aswell.

The Inventors have also recognized the benefits of employing two or moremasks in contact with bare regions of a substrate to pass currentthrough the substrate between the masks without passing the currentthrough a layer deposited onto the substrate. Accordingly, the resistiveheat generated in the substrate by such a system may be more consistentand more efficient when current is passed directly into and out of theunderlying substrate without passing through an intervening layer. Thismay also restrict an area of heat generation within the substrate to bewithin a portion of the substrate corresponding to a target region wherea material is sprayed onto the substrate between the masks. Theinventors have also recognized that such an arrangement may allowmultiple layers of different materials to be deposited in series whilethe substrate is resistively heated through the bare portions maintainedby the masks.

In some embodiments, a system for forming a particle layer on asubstrate includes at least one sprayer configured to electricallycharge and spray particles including at least one selected from thegroup of an electrochemical material, an ionically conductive material,a separator material, an electrically conductive material, a binder,combinations of the foregoing, and/or any other appropriate material forforming a layer within an electrochemical cell toward a substrate.Regardless, such particles may be used independently or in combinationto form an electrode layer (e.g. an anode or cathode), a solid stateelectrolyte layer, a separator layer, or any other desirable materiallayer. The system may also include a first mask movable to selectivelymask a first region of the substrate from the particles and a secondmask movable to selectively mask a second region of the substrate fromthe particles. The first mask and second mask may be clamps, shields, orother suitable movable bodies which may cover the first and secondregions of the substrate from the particles. The first region and secondregion may be disposed on opposite sides of a target region of thesubstrate the at least one sprayer is directed towards so thatcorresponding bare regions of the substrate are disposed on opposingsides of the target region of the substrate coated by the at least onesprayer. Thus, a deposited material layer may be confined to a definedtarget region along a length of the substrate.

In some embodiments, the above noted system may also include a heaterconfigured to heat the substrate. The first mask and second mask may beconfigured as first and second electrodes configured to pass currentthrough the substrate between the first and second masks. According tothis embodiment, the heater may be configured to pass a current from thefirst mask to the second mask through the substrate to resistively heatthe substrate internally. Though, as detailed further below, embodimentsin which different heating methods such as radiative, conductive, and/orconvective heating methods are used by one or more heaters to heat asubstrate are also contemplated as the disclosure is not so limited.

In some embodiments, a process for depositing a layer of a desiredmaterial onto a substrate may include the following. First, a firstregion and a second region that are spaced from one another along alength of a substrate may be masked. Next, the substrate may be heated(e.g., resistively heated). A plurality of particles may then be sprayedonto the substrate. In some embodiments, the particles may be sprayedwithout the use of a solvent. Further, in some embodiments, theparticles may be a mixture of a first material with a binder, a materialpre-coated with a binder, and/or the material itself may be capable ofbinding to the substrate and/or an underlying layer. Regardless, in oneembodiment, the particles may be aerosolized or otherwise turned into aspray of particles directed towards a target region of the substrate inany appropriate fashion. In some instances, the aerosolized particlesmay be appropriately charged prior to being deposited onto thesubstrate. Due to the substrate, and any layers already depositedthereon, being heated, the deposited material may adhere to the heatedsubstrate or layer to form the desired layer disposed thereon.

In some embodiments, it may be desirable to deposit two or more materiallayers on a substrate. In such an embodiment, first particles may beapplied to the substrate including at least one selected from the groupof an electrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material. In somecases, these first particles may form a first electrode layer, such asan anode or cathode, on the substrate when applied. For example, thefirst electrode layer may include both electrochemical materials and asolid electrolyte. Second particles including at least one selected fromthe group of an electrochemical material, an ionically conductivematerial, an electrically conductive material, and a separator materialdifferent from the first particles may then be applied to the substrateon top of the first layer. In an embodiment where the first layer is anelectrode layer, the second particles may be made from a material toform a separator layer and/or solid electrolyte layer disposed on top ofthe electrode layer. In some applications, a second electrode layer maythen be deposited on the separator and/or solid electrolyte layer. Forexample, in one embodiment of a battery electrode manufacturing process,an anode layer, a solid state electrode and/or separator layer, and acathode layer may be sequentially deposited onto a substrate using themethods and systems disclosed herein. Of course, the systems and methodsdescribed herein may be used to form any suitable number of materiallayers for any desired application as the present disclosure is not solimited.

It should be understood that the disclosed deposition system may includeany suitable heater that may be used to heat a substrate during amaterial deposition process. For example, in one embodiment, a heatermay be configured to resistively heat a substrate by passing a currentthrough the substrate to generate internal heat in the substrate.Alternatively, heaters employed with spray deposition systems maytransfer heat to the substrate, and associated deposited layer, in anyappropriate manner including convective heat transfer, conductive heattransfer, and/or radiative heat transfer. For example, appropriate typesof heaters may include, but are not limited to: a radiative heater; aheated surface such as a smooth heated glass or roller surface thesubstrate passes over; a heated oven or other environment the substratepasses through; hot air blowers; or any other appropriate device capableof transferring heat to the substrate. Of course, combinations of theabove heaters are also contemplated as the present disclosure is notlimited to any particular arrangement of heaters for heating asubstrate.

In some embodiments, a system for forming a particle layer on asubstrate includes one or more pairs of calendering rollers configuredto compress, and optionally heat, a substrate and one or more materiallayers deposited on the substrate to densify the one or more materiallayers as they pass between opposing calendering rollers. In someembodiments, the calendering rollers may be disposed at a locationfollowing each sprayer along a manufacturing line, so that depositedmaterial may be calendered to densify and/or fully bond the material tothe substrate prior to depositing additional material layers and/orcompleting a desired layer formation process. Alternatively, there maybe a pair of calendering rollers included in a system disposed at alocation following multiple sprayers along a direction in which thesubstrate moves through the system. The sprayers may deposit separatematerial layers sequentially. Thus, such an arrangement may allowmultiple deposited material layers to be calendered simultaneously by asingle pair of calendering rollers. Accordingly, it should be understoodthat any appropriate number of calendering rollers may be included inthe system at any number of appropriate locations as the disclosure isnot limited to any particular arrangement.

According to some embodiments, a particle layer manufacturing processmay be a semi-continuous or continuous process. In a semi-continuousprocess, a substrate may be intermittently fed through a system by aconveyer constructed to move a substrate through the system relative tothe various sprayers, heaters, calendering rollers, and/or othercomponents. For example, a conveyer may correspond to a pair of rollerswhere a substrate may be unwound from a first roller and wound onto asecond roller to advance a preselected length of the substrate throughthe system between the rollers. At least one sprayer as well as at leasta first and second mask may be disposed between the first roller and thesecond roller along a path of the substrate extending between therollers. The first mask and second mask may be moveable to selectivelycover a first region and second region of the substrate, respectively,while the substrate remains stationary. Next, the at least one sprayermay deposit a material at a target region of the substrate between thefirst and second masked regions. The first and second mask may then bemoved out of contact with the substrate to release or otherwise uncoverthe first region and second region, whereupon the first roller andsecond roller may advance the substrate. This semi-continuous processmay be repeated multiple times for the whole substrate, as the materialis sequentially advanced, the masks cover different regions of thesubstrate, and material is deposited onto multiple target regions alonga length of the substrate while maintaining regions of the substratebetween adjacent target regions bare of the deposited material. Inanother embodiment, the process may be continuous, where the first maskand second mask may move in sync with the substrate as the substrate iscontinuously moved through a system as may occur as a substrate iscontinuously unwound from a first roller and wound onto a second roller.Additional masks may cover other regions of the substrate. Further, atleast one stationary or mobile sprayer may deposit a material onto thesubstrate as the substrate passes through the system. Accordingly, suchan arrangement may allow material to be continuously deposited onto thesubstrate. Of course, systems according to exemplary embodimentsdescribed herein may be used in a continuous, semi-continuous, ornon-continuous manner, as the present disclosure is not so limited.

A system may include any appropriate type of conveyor for transporting asubstrate through a system relative to one or more sprayers used todeposit materials onto the substrate. For example, a conveyer may move asubstrate from an upstream location towards a downstream locationthrough the system. Appropriate types of conveyors may include, but arenot limited to: opposing rollers the substrate may extend between suchthat the substrate may be unwound from one and wound onto the otherroller; movable platforms and/or conveyor belts the substrate isdisposed on; and/or any other appropriate device or construction capableof moving a substrate through a system for depositing one or more layersthere on as disclosed herein.

As used herein, a mask refers to any solid body suitable tosubstantially cover a desired portion of a substrate to inhibitparticles being sprayed, or otherwise deposited, onto the substrate in aregion covered by the mask. In some embodiments, a mask may beconfigured as a clamp, or other selectively moveable component, whichmay be moved into contact with a desired portion of the substrate. Thus,in some embodiments a mask may clamp the substrate, to further inhibitsprayed particles from covering the masked portion of the substrate. Inother embodiments, the mask may be configured as a shield disposedbetween a sprayer and a substrate to effectively deflect particles froma region or portion of the substrate without physically contacting thesubstrate. Accordingly, a mask may be any suitable structure whichinhibits material being deposited onto a substrate such that a portionof the substrate underlying the mask remains bare after a material layeris deposited onto the substrate. Again, while any appropriate structurecapable of masking a substrate may be used, possible constructions mayinclude, but are not limited to, a casing, covering, wrapper, envelope,shield, sheath, and/or any other appropriate structure. Further, thesemasks may be static and/or may be moveable into and out of contact witha substrate depending on the embodiment.

Depending on the particular application, the particles sprayed onto asubstrate noted above may correspond to any appropriate material for usein forming one or more layers within an electrochemical cell including,but not limited to an anode, cathode, separator, and/or solidelectrolyte layers. These materials may include an ionically conductivematerial, an electrochemical material, a separator material, anelectrically conductive material, a binder, combinations of theforegoing, and/or any other appropriate material. Further, depending onthe particular material, the material may be deposited by itself, mixedwith a binder, and/or the material may be pre-coated with a binder.Thus, embodiments in which particles comprising a single material aresprayed onto a substrate as well embodiments in which particlesincluding a combination of different materials are co-sprayed and/orcoaerosolized with one another to form a deposited layer on a substrateare both contemplated as the disclosure is not so limited.

As noted above, in certain embodiments, the described materials andprocesses may be used to form one or more layers to be used in themanufacture of an electrochemical cell. These layers may include one ormore of an anode, cathode, separator layer, solid state electrolytelayer, and/or any other appropriate layer present in a desiredelectrochemical cell. Examples of electrochemical cells may include, butare not limited to, batteries (primary and secondary), super capacitors,fuel cells, and/or any other appropriate electrochemical cell. However,while the particular materials and processes described herein areprimarily directed to electrochemical cells, and more specificallyLi-ion based chemistries, it should be understood that the currentlydescribed methods and devices may be used to manufacture and deposit anyappropriate type of particle material that is mixed with a binder,coated with a binder, and/or has appropriate material properties toadhere to a desired substrate including different types ofelectrochemical cell chemistries as the disclosure is not limited to anyparticular application and/or chemistry.

To facilitate the manufacture of the above noted layers of anelectrochemical cell, it may be desirable to sequentially depositdifferent types of materials in separate layers that are disposed one ontop of the other using the methods described herein. For example, in oneembodiment, first particles including a first electrochemical material,such as an electrochemical material, may be deposited onto an electrodeto form a first active layer corresponding to an anode or cathode of anelectrochemical cell. A second material, such as a first ionicallyconductive material or separator material, may then be deposited ontothe first active layer to form a separator or solid state electrolytelayer on the electrode. A third material, such as a secondelectrochemical material, may then be deposited onto the second layer toform a second active layer corresponding to the other of the anode andcathode of the electrochemical cell. Alternatively, the other activelayer may be deposited onto a separate electrode and assembled with theother layers through either a stacking or winding process. In someembodiments, a high pressure calendering process may be used to helpdensify the various layers either between depositions of the differentlayers and/or simultaneously after each of the layers has been depositedonto the substrate.

Possible electrochemical materials that may be used with the disclosedmethods and systems may include, but are not limited to, lithium cobaltoxide (LCO), lithium nickel manganese cobalt oxide (NMC), lithiummanganese cobalt oxide (LMCO), lithium iron phosphate (LFP), lithiummanganese iron phosphate (LMFP), lithium nickel cobalt aluminum oxide(NCA), lithium titanate (LTO), silicon, sulfur and/or combinationsthereof. While particular types of electrochemical materials have beenlisted above it should be understood that any appropriateelectrochemical material may be used as the disclosure is not limited toonly these materials.

Possible electrically conductive materials that may be used with thedisclosed methods and systems may include, but are not limited to,carbon (e.g., graphite) and/or any other appropriate electricallyconductive material appropriate for use in a particular electrochemicalcell. It should be noted that carbon may also be used as anelectrochemical material (e.g., a lithium ion anode) in certainembodiments.

For the purposes of this disclosure, ionically conductive materials mayinclude materials that facilitate the transport of ions both through thebulk of the material and/or the transport of ions along an interfacebetween the material and a layer of binder material disposed on aparticle surface. For example, Li₂O particles may transport Li ionsthrough the bulk of the particles. In contrast, TiO₂ when combined withpolyethylene oxide (PEO) may exhibit enhanced transport of Li ions whencompared to either of these materials along which, without wishing to bebound by theory, may be due to an enhanced transport of Li ions alongthe interface between the TiO₂ particles and PEO binder. Of course, itis contemplated that certain particle binder combinations may exhibiteither one or both of these effects. However, in either case, thesematerials are still considered to be ionically conducting or ionicallyconductive materials for the purposes of this application.

In view of the above, possible ionically conducting materials that maybe used with the disclosed methods and systems may include one or moreionically conducting ceramics such as metal oxides, and/or metal oxidesthat facilitate the transport of ions along an interface with a binder,such as Al₂O₃, SiO₂, TiO₂, MgO, ZnO, ZrO₂, CuO, CdO, and Li₂O.Alternatively, and/or in combination with the noted metal oxides, theionically conducting material may be an ionically conducting glassessuch as one or more of Li₂S, P₂S₅, and xLi₂S-(1-x)P₂S₅. While particulartypes of ionically conductive materials have been listed above it shouldbe understood that any appropriate ionically conductive material may beused as the disclosure is not limited to only these materials.

In some embodiments, the above noted ionically conducting materials maybe used to form a solid state electrolyte layer. Alternatively, thesematerials may be mixed with one or more other materials such as anelectrochemical material, a separator material, an electricallyconductive material, and/or any other appropriate material to increasean ionic conductivity of that layer.

As noted above, in some embodiments, a separator layer may be formed ona previously deposited material layer, such as an electrode of anelectrochemical cell. In such an embodiment, the separator may be formedof any suitable number of materials, including, but not limited to,polyethelene, prolpropylene, or other polymers. In other embodiments,the separator layer may be formed of ceramic particles mixed with apolymer. In such an embodiment, the ceramic particles may be combinedwith the polymer during a spray deposition process. For example,pre-mixing polymer particles with ceramic particles, or gas-phase mixingand co-depositing polymer particles with ceramic particles may be used.Alternatively, the ceramic particles may be pre-coated with the polymerprior to spray deposition.

Appropriate types of binders that may be used with the disclosed methodsand systems may include, but are not limited to, any appropriatethermoplastic polymer. It should be noted that the deposition ofmaterial layers without the use of a solvent using the methods andsystems described herein may enable the use of binder materials that mayimprove properties of a resulting electrochemical cell, but that are nottypically used in solvent based deposition processes. For example,binders that are more ionically and/or electronically conductive thantypical binders, but that are not easily soluble in typical solvents,may be used to form the pre-coated particles. Accordingly, appropriatepolymers may include, but are not limited to polyvinylidene fluoride(PVDF), polytetrafluoroethylene (PTFE), styrene-butadiene (SBR),polyethylene oxide (PEO), polyacetylene, polyphenylene, polypyrrole,polythiophene, polyaniline, polyphenylene sulfide, and/or combinationsof the above.

Depending on the particular binder being used, it may be desirable toincrease the ionic conductivity of a binder material being used.Accordingly, in some embodiments an ionically conductive salt may bedissolved in a binder to improve the ionic conductivity. In one suchembodiment, a lithium salt may be dissolved in the thermoplasticmaterial of a binder. In such an embodiment, the thermoplastic bindermaterials may correspond to any of the polymers noted herein and mayinclude a lithium salt dissolved therein. Appropriate lithium saltsinclude, but are not limited to, LiClO₄, LiBF₄, LiPF₆, LiAsF₆, LiTf,LiTFSI, LiBETI, LiCTFSI, LiBOB, LiTDI, LiPDI, LiDCTA, and LiB(CN)₄. Inone specific embodiment, a lithium salt may be dissolved in PEO to formPEO-LiX. Of course, other types of salts as well as the inclusion ofnon-lithium based salts may be used depending on the particularchemistry of an electrochemical cell the binder is being used with.

As noted above, in some embodiments, a binder may be applied duringspray deposition of a material layer either as a separate powderco-sprayed with another material and/or the binder may be pre-coatedonto particles of a desired material. In either case, any appropriateamount of binder may be included in a material layer to provide adesired conductivity in combination with the binder material propertiesfor binding a material layer to a substrate or an underlying materiallayer. Accordingly, a material layer including a binder may include aportion of binder that is greater than or equal to 1%, 10%, 20%, or anyother appropriate portion of a binder. Correspondingly, the materiallayer may include a binder in a portion that is less than or equal to40%, 30%, 20%, 10%, or any other appropriate portion. Combinations ofthe above ranges are contemplated including, for example, a materiallayer with a portion of binder between or equal to 1% and 40%, 1% and10%, or any other appropriate portion of binder both greater than orless than that noted above as the disclosure is not so limited.

Particles used with the spray deposition systems and methods describedherein may have any appropriate size including micro and/ornanoparticles. For example, a particle may have a maximum transversedimension (e.g. maximum diameter) that is greater than or equal to 10nm, 50 nm, 100 nm, 250 nm, 1 μm, 100 μm, or any other appropriate size.Similarly, the particles may have a maximum transverse dimension that isless than or equal to 300 μm, 250 μm, 100 μm, 1 μm, 250 nm, or any otherappropriate size. Combinations of the above ranges are contemplatedincluding, for example, particles with a maximum transverse dimensionbetween or equal to 10 nm and 300 μm. Of course, particles withdimensions both greater than and less than those noted above are alsocontemplated as the disclosure is not so limited.

As used herein, the terms coat, coating, pre-coated, as well as othersimilar terms, may refer generally to a layer of material applied to anexterior surface of a particle. Additionally, this coating of materialmay either fully coat the individual particles and/or the coating may beapplied to at least a portion of the particles such that they are notfully coated or encapsulated. Additionally, a coating or encapsulationmay either be applied to a single particle, or multiple particles may becoated or encapsulated within a single outer shell or coating. Forexample, multiple particles, such as two or three particles, may beencapsulated or coated such that they form a single larger particle.Therefore, it should be understood that a plurality of particlesincluding coated particles may correspond to embodiments where eachparticle is coated individually, instances where several particles arecoated such that they form a larger combined particle, particles thatare only partially encapsulated, particles that are fully encapsulated,as well as combinations of these types of particles.

Turning to the figures, specific non-limiting embodiments are describedin further detail. It should be understood that the various systems,components, features, and methods described relative to theseembodiments may be used either individually and/or in any desiredcombination as the disclosure is not limited to only the specificembodiments described herein.

FIG. 1 is a side schematic representation of one embodiment of a spraydeposition system 100 for forming a layer on a substrate. In particular,the spray deposition of FIG. 1 may be configured to form a batteryelectrode including an anode or cathode material. As shown in FIG. 1,the spray deposition system includes a conveyor for moving a substrate101, such as a metal foil, through the system. For example, in thedepicted embodiment, a conveyor may include a first roller 102A and asecond roller 102B between which the substrate is suspended. The firstand second rollers are configured to move the substrate from one rollerto the other roller (e.g., from the first roller to the second roller orfrom the second roller to the first roller). In either case, thesubstrate is unwound from one roller and wound onto the other roller sothat material may be deposited in a continuous or semi-continuousprocess if desired. However, embodiments in which a substrate is movedthrough a spray deposition system without the use of rollers are alsocontemplated as the disclosure is not so limited. The spray depositionsystem also includes at least one sprayer 104 directed towards thesubstrate for depositing a material thereon. For example, in embodimentswhere it is desirable to deposit material on both sides of a substratesimultaneously, two sprayers 104 may be disposed on opposite sides ofthe substrate for depositing material onto two surfaces of the substratein a single process. In either case, the sprayers may be arranged as aspray gun or any other appropriate device capable of aerosolizing, andin some embodiments appropriately charging, a powder that is thensprayed onto a surface of the substrate for a powder coating process.

In the above embodiment, the sprayers are each connected to a reservoir106 which contains a powdered material for deposition on the substrate.In some embodiments, the reservoir may correspond to a fluidized bed, aventure atomizer, a Wright dust feeder, or other appropriate device thatis capable of aerosolizing and/or otherwise transporting the dry powderto the sprayer. As will be discussed further with reference to FIG. 2,the sprayer may charge the particles ejected from the spray gun whichmay facilitate the particles evenly distributing across and adhering toa region of the substrate targeted by the sprayer.

As discussed previously, the powdered material may include anyappropriate material for use in forming one or more layers within anelectrochemical cell including, but not limited to anode, cathode,separator, and/or solid electrolyte layers. These materials may includean ionically conductive material, an electrochemical material, aseparator material, an electrically conductive material, a binder,combinations of the foregoing, and/or any other appropriate material.Further, depending on the particular material, the material may bedeposited by itself, mixed with a binder, and/or the material may bepre-coated with a binder.

As shown in the embodiment of FIG. 1, the spray deposition system alsoincludes first masks 108A and second masks 108B which are coupled tofirst mask actuators 110A and second mask actuators 110B, respectively.According to the embodiment of FIG. 1, the first masks and second masksare configured as clamps which close on upper and lower surfaces of thesubstrate 101 to selectively grasp and cover regions of the substrate tokeep them bare during a spray deposition process. However, embodiments,in which first and second masks are only applied to a single side of asubstrate are also contemplated. The position of the first and secondmasks are controlled by the actuators such that the masks are moveablebetween a first position in which they are in contact with the substrateand a second position in which they are not in contact with thesubstrate. For example, the first and second mask actuators may move thefirst and second masks closer to, or further away, from the substrate.The first mask actuators and second mask actuators may beelectromechanical actuators (e.g., linear actuators, servomotors, DCmotors, brushless motors, etc.), pneumatic actuators, hydraulicactuators, and/or any other appropriate actuator suitable for moving themasks relative to a substrate. The first and second mask actuators arecontrolled by a first mask actuator controller 112A and a second maskactuator controller 112B, which may control a supply of electricity,air, and/or hydraulic fluid employed by the mask actuators to move themasks into or out of contact with the substrate. Of course, in otherembodiments, a spray deposition system may employ a single mask actuatorcontroller or any other suitable number of mask actuator controllerswhich control any suitable number of mask actuators, as the presentdisclosure is not so limited. Further, these controllers may include atleast one hardware processor and at least one associated non-transitorycomputer-readable storage medium storing processor executableinstructions that, when executed by the at least one hardware processorcontrol the actuators and other components of the system to perform themethods described herein.

According to the embodiment of FIG. 1, the first and second masks 108A,108B are configured to pass a current supplied by an associated powersource between the first and second masks through the substrate 101 toresistively heat the substrate between the masks in a region the one ormore sprayers 104 are directed towards. That is, the passage of currentthough the substrate in combination with the internal electricalresistance of the substrate generates internal heat in the substrate inthe region of the substrate between the first and second masks. Forexample, the first and second masks may be configured to function aselectrodes which make electrical contact with the substrate when themasks are in a contact with the substrate to mask a bare region of thesubstrate from sprayed particles. Depending on the particularembodiment, the first and second masks may be composed of any suitableelectrically conductive material, or may include one or moreelectrically conductive portions, so that current may be passed throughthe substrate via the first mask and second mask. It should be notedthat current may be passed in any suitable direction though thesubstrate. That is, in some embodiments, the electrical current may bepassed from the first masks 108A to the second masks 108B, and in otherembodiments, the electrical current may be passed from the second masksto the first masks as the disclosure is not limited in this fashion.Further, the conductive portions of the first masks and second masks incontact with the substrate may be suitably sized so as to avoid hotspots being formed via current concentration on the substrate and topromote even resistive heating. For example, in one embodiments, anelectrically conductive portion of the first mask and second mask mayspan an entire width of the substrate to mitigate potential hot spotformation, though smaller electrical contact sizes are alsocontemplated. In some embodiments, the mask actuator controllers 112A,112B may also selectively pass electrical current to the first masks108A and second masks 108B so the number of disparate controllers may bereduced. Of course, the electrical current may be passed through themasks using any suitable number of independent or combined controllers,as the present disclosure is not so limited.

While the embodiment FIG. 1 uses first and second masks as electrodes topass a current through the substrate, it should be noted that anysuitable arrangement of electrodes may be employed to pass currentthrough the substrate. For example, conductive rollers or conductivebrushes at different locations may pass the current through thesubstrate. For example, in some embodiments, a conductive roller orbrush may pass current through the substrate and one or more layers ofmaterial deposited by the sprayers. That is, current may be passed intoor out of the underlying substrate via conductive rollers or brushes inelectrical contact with a material layer disposed on the substrate. Inone such embodiment, calendering rollers may be used to pass currentinto or extract current from the substrate through the material layer.In this embodiment, another roller or brush may be used to pass currentinto or extract current directly from the substrate at a location of thesubstrate which has yet to undergo spray deposition. Of course, anysuitable resistive heating arrangement may be employed, as the presentdisclosure is not so limited.

As shown in FIG. 1, the spray deposition system 100 may also include apair of calendering rollers 114 which may be used to densify a depositedmaterial layer. The calendering rollers may be heated and apply asufficiently high pressure to the substrate and any material layerswhich may be disposed on the substrate to densify the layer to a desiredthickness and bond the layer to the substrate as the substrate passesbetween the pair of calendering rollers. Accordingly, after a depositedmaterial layer is passed through the calendering rollers, the materiallayer may have a uniform density and thickness, in addition to beingdenser than the non-calendered layer. In some embodiments, thecalendering rollers may be used to densify multiple material layerssimultaneously.

FIG. 2 is a side schematic representation of the spray deposition system100 of FIG. 1 during a material deposition process. As shown in FIG. 2,the first masks 108A and the second masks 108B have been moved intocontact with the substrate 101 to mask off (i.e., cover) bare regions ofthe substrate on both sides of the substrate so that the depositedmaterial does not accumulate on the bare masked regions. Though again,embodiments in which a material layer is deposited on a single side ofthe substrate and a single pair of masks are used are also contemplated.While the masks are in the clamped position, the first and secondrollers 102A and 102B which control movement of the substrate 101extending there between are held stationary. As discussed previously,the first masks and second masks may be configured as electrodes, andare in electrical communication with one another though the substrate inthe clamped state shown in FIG. 2. Once appropriately positioned,current is passed through the first masks and second masks toresistively heat the substrate between the first masks and the secondmasks. As shown in FIG. 2, the two sprayers 104 located on opposingsides of a target region of the substrate between the masks charge andaerosolize first particles 200 and then spray the first particlestowards the opposing exposed surfaces of the substrate. The firstparticles are fed to the sprayers from reservoirs 106. The spraydeposition process may be continued until a suitable amount of the firstparticles have been deposited on the substrate between the first andsecond masks. The thickness of a deposited layer may be controlled bythe deposition rate of material emitted from the spray guns, time ofdeposition, and/or other appropriate control parameters. In someembodiments, the electrical potential applied to the substrate via thefirst masks and second masks may be selected so that the chargedparticles are attracted towards the substrate. For example, the chargedparticles may be charged with a large negative or positive potential andthe potential applied by the first and second masks may be lower and/oropposite that of the charged particles so that the charged particles areattracted to and stick to the substrate when sprayed. In one embodiment,one of the first masks and second masks may be grounded, so that atleast a portion of the substrate adjacent the grounded mask is alsogrounded.

As mentioned previously above, depending on what type of material issprayed on to a substrate to form a deposited layer, different types ofstructures may be formed using the described process. For example, thedisclosed system may be used to deposited electrode layers, separatorlayers, solid state electrolyte layers, electrically conductive layers,and/or any other appropriate material layer. Accordingly, while severalpossible embodiments are described above, it should be understood thatthe presently disclosed materials and processes should not be limited tojust these types of applications and structures.

It should be noted that while a reel-to-reel spray deposition system 100is shown in FIGS. 1-2, alternative spray deposition systems may beemployed which do not include the first roller 102A and the secondroller 102B. In one such an embodiment, the first masks 108A and secondmasks 108B may be configured to hold a substrate stationary during spraydeposition by the sprayer 104. That is, the first masks and second masksmay be used to selectively grasp an individual substrate that ispositioned between and held in place by the masks, so that a spraydeposition process may be performed non-continuously.

FIG. 3 is a side schematic representation of the spray deposition system100 of FIG. 1 during a material deposition process after a firstmaterial layer 202 has been deposited on the substrate 101. As shown inFIG. 3, a material layer of a desirable thickness has been deposited onthe substrate from the sprayers 104. The first masks 108A and secondmasks 108A have been moved to a released position such that they aredistanced from a surface of the substrate so that the substrate may bemoved laterally through the system between the masks. That is, in theembodiment of FIG. 3, the first mask actuators 110A and the second maskactuators 110B have moved the first masks and second masks away from andout of contact with the substrate, respectively. As denoted by the arrowadjacent the second roller 102B, when the first masks and second masksare out of contact with the substrate, the first roller 102A and secondroller 102B may rotate, or another appropriate conveyor construction maybe operated, to move the substrate through the system. The masks may beappropriately distanced from the substrate in the open configuration toavoid contacting the deposited layers as the substrate is moved. In thedepicted embodiment, the first roller and second roller rotate clockwiserelative to the page to unwind the substrate from the first roller andwind the substrate on the second roller though the disclosure is notlimited to the direction and/or method of movement of a substratethrough a system. Accordingly, the first and second rollers move thedeposited material layer toward the calendering rollers 114 to calenderthe deposited material layer.

FIG. 4 is a side schematic representation of the spray deposition system100 of FIG. 1 during a material deposition process following the stateshown in FIG. 3. As shown in FIG. 4, the first deposited material layeris fed through the calendering rollers 114 so that a calendered materiallayer 204 is formed as the first material is densified. In someembodiments, the calendering rollers may be heated to facilitate thedensification and bonding of the deposited material layer to thesubstrate. As shown in FIG. 4, when the first deposited material layeris moved past the second masks 108B, the first and second rollers 102A,102B may stop the substrate so that another first material layer may bedeposited on the substrate. That is, when the bare region which wasfirst covered by the first masks 108A is aligned with the second masks108B, the substrate may be stopped and the first and second masks movedto grasp the substrate. The first mask actuators 110A and second maskactuators 110B may move the first masks and second masks towards andinto contact with the substrate so that bare regions of the substrateare covered. As shown in FIG. 4, the sprayers 104 may deposit chargedfirst particles 200 from the reservoirs 106 onto both sides of thesubstrate while the first and second masks shield bare regions fromparticle deposition and pass a current through the substrate toresistively heat the substrate. Accordingly, the spray deposition systemof FIGS. 1-4 sequentially deposits material layers onto a substratewhich are separated by bare regions shielded by the masks. As notedpreviously, the bare regions may help to ensure consistent resistiveheating of the substrate in a target region of the sprayers, while alsoproviding regions of bare substrate which facilitate cutting of thesubstrate and/or the attachment of electrical leads to the substrateduring a later formation step.

It should be understood that the calendering rollers 114 depicted in theabove embodiment may be disposed at any appropriate position within thesystem along a length of the substrate extending through the system. Forexample, the calendering rollers may be positioned as depicted in thefigures, or they may be positioned at a location such that when a newtarget region of the substrate is positioned between the masks, thecalendering rollers may be located above a bare region of the substrateto avoid applying heat and/or pressure to a portion of a depositedmaterial layer for an extending period of time. Accordingly, thecalendering rollers are not limited to only the depicted locations.

FIG. 5 is a top schematic representation of the spray deposition system100 of FIG. 1 during a material deposition process. The state shown inFIG. 5 corresponds to a state following that shown in FIG. 4, wheremultiple first material layers 202 have been deposited and moved throughcalendering rollers 114 to form multiple calendered first materiallayers 204. Each of the calendered first material layers is separatedfrom an adjacent calendered first material layer by a bare region 118 ofthe substrate corresponding to the regions covered by the first mask108A and the second mask 108B. A next target region 116 of the substrateis aligned between the first mask 108A and the second mask 108B formaterial deposition, with a previously deposited first material layerhaving been partially and/or fully calendered depending on the locationof the calendering rollers along a length of the substrate. Further, inthis particular configuration the portion of the substrate previouslyshielded by the first mask is now aligned with and shielded by thesecond mask.

FIG. 6 is a top schematic representation of the spray deposition system100 of FIG. 1 following the state shown in FIG. 5. As shown in FIG. 6,the sprayer 104 sprays first particles towards the target region of thesubstrate to form another first material layer 202 while bare regionsadjacent the target region are covered by the first mask 108A and secondmask 108B. The first mask and second masks may be in contact with theunderlying substrate during the spraying process so that theyeffectively cover the underlying regions of the substrate and inhibitsprayed particles from being deposited on the bare regions. As shown inFIG. 6, the first mask and second mask cover an entire width of thesubstrate, though embodiments in which the masks extend partially acrossa width of the substrate and/or exhibit different arrangements and/orshapes are also contemplated. In either case, once the masks are placedin contact with the substrate, current may be passed between the firstand second masks through the substrate to resistively heat the targetregion of the substrate while the first particles are deposited from thesprayer 104.

FIG. 7 shows the continuation of the process from FIG. 6. From the stateshown in FIG. 6 where an additional first material layer 202 isdeposited in a target region of the substrate, the first mask 108A andsecond mask 108B are moved out of contact with the substrate by anappropriate distance so as to not interfere with the substrate or thedeposited material layer when the substrate is moved. The first roller102A and second roller 102B, or other appropriate substrate handlingsystem, are then operated to move the substrate toward the calenderingrollers 114. Once the next target region 116 is aligned between thefirst and second masks, the first and second rollers are stopped. Fromthis state, the first and second mask may be moved back into contactwith the substrate at a bare region so that an additional material layermay be deposited. This process may be repeated as many times as desiredto create a series of sequentially arranged deposited material layersand bare regions along a length of a substrate.

FIGS. 8-9 are a top and side schematic representation, respectively, ofa material produced by the spray deposition system of FIGS. 1-7. Asnoted previously, the end material produced by the spray depositionsystem of FIGS. 1-7 may be a substrate 101 having alternating regions ofdeposited material layers 204 and bare regions 118 located along alength of a substrate. Further, in some embodiments, the material layersare calendered material layers, and each of the deposited calenderedmaterial layers may be at least partially separated from the othercalendered material layers by a bare region. Accordingly, segments ofthe substrate may be easily separated (i.e., cut) along the bareregions, producing disparate electrodes which may have electrical leadswelded, soldered, or otherwise coupled to the substrate within the bareregions during a later formation process. Such a material may greatlysimplify the manufacturing of batteries or other electrochemical cells,as it eliminates an additional process step of removing material fromthe substrate prior to calendering and/or attachment of the electricalleads.

FIGS. 10-13 are side schematic representations of another embodiment ofa spray deposition system 300 where multiple materials are sequentiallydeposited onto a substrate. Similar to the embodiment of FIGS. 1-7, thedeposition system shown in FIG. 10 may include a first roller 302A and asecond roller 302B which allows a substrate 101 to be continuouslyunwound from one roller and wound onto the other roller. As shown inFIG. 10, the spray deposition system includes two distinct stationswhere different material layers are deposited in sequence. The firststation of the spray deposition system includes first sprayers 304Acoupled to first reservoirs 306A which deposit first particles on thesubstrate. First masks 308A and second masks 308B also form part of thefirst station, and are configured to selectively contact the substrateto cover bare regions and define a first target region of the substratethere between for material deposition. Like the embodiment of FIGS. 1-7,the first masks and second masks are controlled by first mask actuators310A and second mask actuators 310B, respectively. The first maskactuators and second mask actuators are in turn controlled by a firstmask actuator controller 312A and a second mask actuator controller312B. Finally, the first station may include a first set of calenderingrollers 314A downstream from the first work station which may beconfigured to densify a first material layer once deposited by the firstsprayers 304A. The second station of the spray deposition systemincludes components similar to those of the first station. The secondstation includes second sprayers 304B coupled to second reservoirs 306B.The second station also includes third masks 308C and fourth masks 308Dwhich define a second target region there between for depositingmaterial onto the substrate. The third and fourth masks may be coupledto third mask actuators 310C and fourth mask actuators, respectively,which in turn are controlled by a third mask actuator controller 312Cand a fourth mask actuator controller 312D. Finally, the second stationmay also include second calendering rollers 314 downstream from thesecond station which are configured to densify a second material layerdeposited by the second sprayers. Thus, the spray deposition system ofFIGS. 10-13 is configured to sequentially deposit and calender twoseparate material layers on a substrate. Of course while two stationsfor depositing two layers are described above, it should be understoodthat a system may include any number of deposition stations forsequentially depositing any number of different material layers as thedisclosure is not limited to the number of deposition stations forincluded in a system.

In the state shown in FIG. 10, the spray deposition system is in astarting state where no material layers have been deposited. Such astate may exist when a roll of the substrate 101 is first connected tothe first roller 302A and the second roller 302B. As shown in FIG. 10,each of the first, second, third, and fourth masks 308A-D are distancedfrom the substrate in this starting state.

FIG. 11 depicts the spray deposition system of FIG. 11 during a firstmaterial layer 202 deposition. As shown in FIG. 11, the first masks 308Aand second masks 308B have been moved to contact the substrate.Accordingly, bare regions of the substrate disposed underneath the firstand second masks are shielded such that these regions are maintained ina bare uncoated state as first particles 200 are fed from the firstreservoirs 306A and are sprayed from the first sprayers 304A towards thesubstrate to form first material layers 202 on opposing sides of thesubstrate. Similarly to the embodiment of FIGS. 1-7, the first sprayers304A may electrically charge the first particles 200, so that theparticles are attracted to the substrate and evenly disperse between thefirst masks and second masks. According to the embodiment of FIGS.10-13, the substrate may be configured to be heated resistively. Asshown in FIG. 11, the first masks 308A may function as a negative,grounded, or low potential electrode and the second masks 308B mayfunction as a positive or high potential electrode, so that current ispassed from the second masks to the first masks through the substrate toheat the substrate. Thus, the first masks and second masks both shieldbare regions from material deposition and function as a heater for thesubstrate. Of course, while the embodiment of FIG. 11 is configured topass current from the second masks to the first masks, the direction ofcurrent may be reversed in other embodiments (i.e., with the first maskshaving a positive or high potential and the second masks having anegative, grounded, or low potential), as the present disclosure is notso limited.

Once a sufficient amount of the first particles 200 have been depositedinto a first material layer 202, the spray deposition system proceeds tothe state shown in FIG. 12. As shown in FIG. 12, the first masks 308Aand second masks 308B have been moved to a distanced non-contactingposition relative to the substrate by the first mask actuators 310A andthe second mask actuator 310B. The second masks 308B may be distancedfrom the substrate by a dimension sufficient for the second masks toclear the first material layer 202 as the first roller 302A and secondroller 302B translate the first material layer and substrate through thefirst calendering rollers 314A towards the second deposition station.The first and second rollers move the substrate until a desired portionof the substrate is disposed between the third masks 308C and the fourthmasks 308D, which may be arranged and separated from one another by adistance equal to that of the separation between the first masks andsecond masks. Accordingly, the third masks and fourth masks may bealigned with the corresponding bare regions of the substrate previouslycovered by the first masks and second masks as the spray depositionsystem proceeds to the state shown in FIG. 13.

As shown in FIG. 13, the previously deposited first material layer 202has been moved to be aligned between the third masks 308C and fourthmasks 308D. The rollers then stop the substrate, so that additionalmaterial layers may be deposited and the masks may be moved to contactthe substrate in the bare portions of the substrate aligned with themasks. As shown in FIG. 13, the third masks 308C and fourth masks 308Dhave been moved into contact with the substrate 101 by the third maskactuators 310C and fourth mask actuators 310D, respectively, so that thesubstrate is grasped by the third and fourth masks. Likewise, the firstmasks 308A and second masks 308B have also been moved into contact withanother portion of the substrate by the first mask actuators 310A andsecond mask actuators 310B. Accordingly, each of the first, second,third, and fourth masks are in direct contact with and shield thecorresponding portions of the substrate while particles are depositedfrom the first sprayers 304A and the second sprayers 304B onto thesubstrate. As shown in FIG. 13, the first sprayers deposit firstparticles 200 onto opposing sides of the substrate to form an additionalfirst material layer on the substrate. Meanwhile, the second sprayers304B deposit second particles 206 fed from the second reservoirs 306Bonto the opposing calendered first material layers 204 to form secondmaterial layers 208 on opposing sides of the substrate. When the layeris subsequently translated through the system towards the second roller302B, the substrate as well as the first and second layers may passthrough the second calendering rollers 314B prior to being wound ontothe second rollers.

As shown in FIG. 13, multiple material layers may be depositedsimultaneously at the separate stations. As noted previously, thesubstrate may be resistively heated in the target regions as theparticles are deposited on the substrate. According to the embodiment ofFIGS. 10-13, the third masks 308C and fourth masks 308D may beconfigured as electrodes which pass a current through the substrate atthe second station of the spray deposition system. However, to avoidresistive heating of the substrate between adjacent deposition systems(e.g. between the second and third masks), the third masks and fourthmask may pass a current in an opposite direction than that of the firstmasks 308A and second masks 308B. That is, as shown in FIG. 13, thesecond masks 308B and third masks 308C may be configured as positive orhigh potential electrodes, whereas the first masks 308A and fourth masks308D may be configured as negative, grounded, or low potentialelectrodes. Accordingly, current may pass from the second masks or thirdmasks outward in opposite directions towards either the first masks orfourth masks respectively. Therefore, the masks adjacent to one otherbetween the first station and second station may have an equalpotential, so that current is not passed from the third masks to thesecond masks. Thus, this arrangement of masks may allow current to bepassed through the substrate exclusively in target regions which aresubject to particle deposition as opposed to heating the entirety of thesubstrate. Such a configuration may reduce energy consumption orotherwise improve the efficiency of the spray deposition process. Inaddition to the above, in embodiments where rollers are not used betweensequentially located deposition stations where material is sprayed ontotwo or more adjacent target regions of a substrate, a single mask may bedisposed between adjacent target regions and may function as anelectrode for heating both target regions due to the use of alternatinghigh and low potential masks located along a length of the substrate.

In view of the above, it should be noted that the masks may be arrangedwith any suitable positive, negative, relative potential, or groundedpotential so as to isolate current passage through the target regions ofa substrate. Furthermore, in other embodiments, additional stations maybe added to the spray deposition system with the masks in adjacentstations sharing an equivalent or similar potential so as to inhibitcurrent transmission through the substrate between the stations.However, in some embodiments, the current may not be isolated toparticular stations and any desired portion of the substrate such anylength, and potentially the entire, substrate may be resistively heatedas the present disclosure is not limited to embodiments where resistiveheating of the substrate is limited to being within the confines of theone of more deposition stations of the system.

The process may continue to perform deposition cycles and cyclicallymove the substrate through the system as shown in FIG. 13 until a supplyof substrate is exhausted. That is, the first, second, third, and fourthmasks 308A-D may be moved out of contact with the substrate and thefirst roller 302A and second roller 302B may feed the first materiallayer 202 through the first calendering rollers 314A and the secondmaterial layer 208 through second calendering rollers 314B. Accordingly,after the second material layer is calendered, it may be wound onto thesecond roller 302B. The first and second rollers may stop the substratewhen the next uncoated first material layer 202 is aligned between thethird and fourth masks so that the state of FIG. 14 may be repeated.Thus, the spray deposition system may perform a semi-continuous processby advancing the substrate, stopping, depositing material layers, andadvancing the substrate again. The resulting material formed may have asequence of regions having first material layers 202 and second materiallayers 208 disposed on top of the first material layers separated bybare regions of the substrate.

While the embodiment of FIGS. 10-13 is shown having multiple stationswhich deposit material layers in sequence after moving the substrate 101between the stations, in other embodiments the stations may be combinedinto a single station where multiple material layers are depositedwithout moving the substrate. For example, in some embodiments, multiplereservoirs of materials may be coupled to one or more sprayers so that afirst material layer may be deposited and then a second material layermay be deposited afterward without moving the substrate or any maskscontacting the substrate. In another embodiment, multiple sprayerscoupled to separate reservoirs may be proximate one another so that botheffectively target the same region of the substrate. In this embodiment,a first sprayer may deposit a first material layer and a second sprayermay deposit a second material layer on top of the first material layerwithout moving the substrate. Of course, a spray deposition system mayuse any suitable number of stations, sprayers, reservoirs, and masks, asthe present disclosure is not so limited.

FIGS. 14-15 are top and side schematic representations, respectively, ofa material produced by the spray deposition system of FIGS. 10-13. Asshown in FIGS. 14-15, calendered second material layers 208 are disposedon top of calendered first material layers 204 which are disposed onopposing sides of a substrate 101. Each section of calendered firstmaterial layer and second material layer is separated from the adjacentsections of deposited material layers by a bare region 118 of thesubstrate. As noted previously, such an arrangement improvesmanufacturing processes in which is desirable to easily separate thesegments of material layers and/or join the substrate to anotherstructure such as an electrical lead (e.g., by welding or soldering).

In some embodiments, the material of FIGS. 14-15 may be used to formmultiple separate electrodes. In this embodiment, the calendered firstmaterial layer 204 may be formed using an electrochemical material(i.e., an anode or cathode material). In such an embodiment, thecalendered second material layer 210 may be a separator and/or solidstate electrolyte layer. In other embodiments, the first calenderedmaterial layer may also include a binder and/or a solid stateelectrolyte. Of course, any suitable material or mixture of materialsmay be used to form the calendered first material layer and secondmaterial layer, as the present disclosure is not so limited.

FIGS. 16-17 are top and side schematic representations of one embodimentof a material produced by a spray deposition system. The material ofFIGS. 16-17 is similar to that of FIGS. 14-15, having a calendered firstand second material layers 204 and 210. Additionally, a calendered thirdmaterial layer 214 may be disposed atop the second material layerslocated on opposing sides of the substrate. In one embodiment, the firstmaterial layer 204 may include an electrochemical material to form afirst electrode layer (e.g. an anode or cathode). Correspondingly, thesecond material layer 210 may be an ionically conductive material toform a solid state electrolyte or a separator material to form aseparator layer. The third material layer may be a second electrodelayer comprising a different electrochemical material than that of thefirst electrode layer. Such an arrangement may be useful for formingmultiple battery electrodes on a single substrate prior to use insubsequent battery formation processes. Of course, while specificmaterial layers are discussed above, any materials or material mixturesmay be deposited in any desirable order and in any number of layers asthe present disclosure is not so limited.

FIGS. 18-21 are side schematic representations of yet another embodimentof a spray deposition system 400 during a material deposition process.In contrast to the previously described embodiments which performed anon-continuous or semi-continuous process, the spray deposition systemof FIGS. 18-21 is configured to form material layers on a substrate 101in a continuous process where the substrate is constantly unwound from afirst roller 402A and wound onto a second roller 402B. As shown in FIG.18, the spray deposition system includes first sprayers 402A coupled tofirst reservoirs 406A that direct sprays of material towards opposingsurfaces of the substrate in a first target region and second sprayers404B coupled to second reservoirs 406B that direct sprays of materialtowards opposing surfaces of the substrate in a second target region.The first and second sprayers deliver first particles and secondparticles, respectively. The spray deposition system also includes firstmasks 408A and second masks 408B which are controlled by first maskactuators 410A and second mask actuators 410B. The first mask actuatorsand second mask actuators are operatively coupled to tracks 412 whichare configured to allow the masks to move in sync with the substratewhile maintaining contact with the substrate to shield bare regions ofthe substrate as the first particles and second particles are deposited.In some embodiments, the tracks 412 may be continuous, so that masks arerepeatedly recirculated within the system to mask the substrate as thesubstrate is moved from the first roller to the second roller. The masksactuators may be linked via a chain, belt, or other appropriatestructure which maintains a predetermined distance between each of themasks so that material layers are deposited in equal length segments. Ofcourse, the masks may be separated by any appropriate equal, non-equaldistances, and/or variable distances as the present disclosure is not solimited. As shown in FIG. 18, third masks 408C and third mask actuators410C are following the first masks and second masks along the track.

According to the state shown in FIG. 18, the first masks 408A and secondmasks 408B have grasped the substrate 101 to effectively mask bareregions of the substrate shielded by the masks. The first masks andsecond masks define a target region of the substrate between them wherethe material layers are deposited. As shown in FIG. 18, as the targetregion between the first masks and second masks traverses across thefirst sprayers 404A, the first sprayers deposit first particles 200 ontothe substrate to form a first material layer. While the first particlesflow from the first reservoirs 406A, they may be charged by the firstsprayer 404A, and sprayed onto the substrate to form the first materiallayer. The substrate, first masks, and second masks may move at aconstant speed from the first roller toward the second roller. Accordingto this embodiment, the thickness of the first material layer may becontrolled by the deposition rate of material emitted from the firstsprayer 404A, a speed of the substrate 101, and/or other appropriatecontrol parameters. While the first particles 200 are being ejected fromthe first sprayer, the substrate may be heated resistively by currentpassed through the first masks and second masks. According to someembodiments, and as shown in FIG. 18, the masks may be arranged withalternating potentials to ensure current is passed through each targetregion to heat the target region as it passes underneath one of thefirst sprayers 404A and second sprayers 404B. More specifically, thefirst masks have a positive or otherwise high potential and the secondmasks and third masks have a negative, grounded, or lower potential sothat current flows from the first masks to the second masks and/or thirdmasks. That is, in the state shown in FIG. 18, current is passed fromthe first masks to the second masks and from the third masks to thefirst masks.

FIG. 19 depicts a continuation of the spray deposition process from thestate shown in FIG. 18. As shown in FIG. 19, the first material layer202 has been deposited and the first sprayers 404A have ceased spraying.The substrate 101, first masks 408A, second masks 408B, and third masks408C have moved further toward the second roller 402B. Once the thirdmask 408C is suitably adjacent the substrate, the third mask actuators410C may move the third masks into contact with the substrate to graspthe substrate and define another target region of the substrate betweenthe first masks and the third masks. As noted previously, each of themasks defines a bare region which is covered or shielded from thematerials sprayed by the first sprayers 404A and second sprayers 404B.

It should be noted that while mask actuators are employed in theembodiment of FIGS. 18-21, the masks may be moved into or out of contactwith the substrate using the track. For example, in some embodiments,the track may move the masks closer to the substrate along a particularportion of the track and move the masks further away from the substratealong other portions of the track to control relative movement of themasks relative to the substrate. Thus, these track portions may bearranged so that the masks are passively brought into and out of contactwith regions of the substrate that are to be masked during a depositionprocess. In some embodiments, mask actuators may be combined withvarious track shapes to move the masks in any desirable directionrelative to the substrate, as the present disclosure is not so limited.

FIG. 20 continues the material deposition process from the state of thespray deposition system 400 shown in FIG. 19. As shown in FIG. 20, thesubstrate 101, first masks 408A, second masks 408B, and third masks 408Chave continued to move toward the second roller 402B in sync with oneanother. Each of the first, second, and third masks has maintainedcontact with the underlying substrate and has maintained bare regionswhere the substrate is contacted by the masks. In the state of FIG. 20,the target region of the substrate defined by the first and second masksis adjacent the second sprayers 404B, which correspondingly depositsecond particles 206 from second reservoirs 406B onto the first materiallayer 202 to form a second material layer 208. Meanwhile, the targetregion of the substrate defined by the first and third masks ispositioned adjacent the first sprayers which deposit first particles 200into a first material layer disposed directly on the substrate. Whileeach of these layers is being deposited, the substrate may be heatedresistively by current passed from the first masks 408A to both thesecond masks 408B and the third masks 408C. Of course, in otherembodiments, the direction of current passage may be reversed and passedfrom the third masks and second masks to the first mask, as the presentdisclosure is not so limited. As shown in FIG. 20, fourth masks 408D andfourth mask actuators 410D may follow the third masks along the track412 to define yet another target region between the third masks and thefourth masks.

FIG. 21 depicts the material deposition process following on the stateshown in FIG. 20. As shown in FIG. 21, the substrate 101, first masks408A, second masks 208B, third masks 408C, and fourth masks 408D havemoved further toward the second roller 402B. The deposition of thesecond material layer 208 between the first and second masks has beencompleted and the second masks have been moved out of contact with thesubstrate by the second mask actuators 410B. The released portion of thesubstrate including the second material layer 208 and first materiallayer 202 are fed into calendering rollers 414 which densify the firstand second material layers simultaneously prior to winding the substrateonto the second roller 402B. As the second masks have released thesubstrate, the fourth masks 408D have been moved into contact with thesubstrate by the fourth mask actuators 410D. Accordingly, the thirdmasks 408C and fourth masks 408D may define yet another target regionbetween them for material deposition.

While the embodiment shown in FIGS. 18-21 depicts timing the first andsecond sprayers 404A, 404B so that material is deposited in bursts(i.e., non-continuously), in other embodiments the first sprayers andsecond sprayers may deposit material constantly. That is, firstparticles and second particles may be ejected continuously from thefirst sprayers and second sprayers as the substrate and masks move fromthe first roller 402A toward the second roller 402B. According to thisembodiment, the sprayers may spray particles directly at the substrateas the masks and substrate pass underneath the sprayers and are locatedin a desired range. However, as the masks shield the underlyingsubstrate, bare regions of the substrate may still be maintainedunderneath the masks in such an arrangement.

FIG. 22 is a top schematic representation of yet another embodiment of aspray deposition system 500 during a continuous material depositionprocess. According to the embodiment of FIG. 22, the spray depositionsystem is similar to that of FIGS. 18-21, except that the systemdeposits three material layers in sequence at different stations. Asshown in FIG. 22, the system includes a first roller 502A and a secondroller 502B which translates a substrate 101 by unwinding the substratefrom the first roller and winding the substrate onto the second rollerin a reel-to-reel process. The system includes a first sprayer 504A,second sprayer 504B, and third sprayer 504C which each deposit differentmaterials or material mixtures on the substrate in sequence. The systemalso includes a plurality of masks 508 and mask actuators 510 arrangedon a continuous track 512 which allows masks to be moved into or out ofcontact with the substrate in a continuous motion. For clarity, themasks and mask actuators in contact with the substrate are labeled as afirst mask 508A, first mask actuator 510A, second mask 508B, second maskactuator 510B, third mask 508C, third mask actuator 510C, fourth mask508D, and fourth mask actuator 510D. As noted previously with referenceto the embodiment of FIGS. 18-21, the masks define target regionsbetween them for material deposition, where each target region will beseparated from adjacent target regions by a bare region of the substrateshield by the masks. According to the embodiment of FIG. 22, the firstmask 508A and the third mask 508C are configured as grounded, negative,or otherwise low potential electrodes. In contrast, the second mask 508Band fourth mask 508D are configured as positive or otherwise highpotential electrodes, so that electrical current flows from the secondand fourth electrodes to the first and third electrodes, respectively,to resistively heat the substrate as material is deposited by each ofthe sprayers.

As shown in the embodiment of FIG. 22, the spray deposition systemdeposits three distinct material layers which are calenderedsimultaneously before being wound onto the second roller 502B. That is,as the substrate passes the first sprayer 504A, a first material layer202 is formed on the substrate. As the substrate continues and ispositioned adjacent the second sprayer 504B, the second sprayer depositsa second material layer 208 on top of the first material layer.Continuing on, the substrate moves adjacent the third sprayer 504C whichdeposits a third material layer 212 on top of the second material layer.After the third material layer is deposited, the mask nearest thecalendering rollers 514 (which in the state shown in FIG. 22 is thefourth mask 508D) is moved out of contact with the substrate and thesubstrate including the three layers is passed through the calenderingrollers 514. As the three layers are calendered, they are densifiedsimultaneously to yield a calendered three-layer composite which iswound onto the second roller 502B. As noted previously, the three layersmay include any desirable materials or mixtures of materials, as thepresent disclosure is not so limited.

It should be noted that while an ovular track is shown and describedwith reference to the embodiment of FIG. 22, it should be understoodthat a track may have any appropriate shape, and any number of tracksmay be used for handling the masks of a system, as the disclosure is notlimited to any particular number and/or arrangement of tracks within asystem. Further, in some embodiments, a spray deposition system mayinclude multiple short tracks associated with multiple sprayers. In thisembodiment, masks may move to a starting position of the track, contactthe substrate and move with the substrate concurrently until the end ofthe track. When the mask reaches the end of the track, the mask may moveout of contact with the substrate and travel in a direction opposite toa direction of travel of the substrate to return to the startingposition of the track. Thus, the disclosed systems may include anysuitable track type and/or number of tracks as the present disclosure isnot so limited.

FIG. 23 is a side schematic representation of yet another embodiment ofa spray deposition system 100 during a material deposition process. Theembodiment of FIG. 23 is similar to that of FIGS. 1-7, except thatinstead of resistively heating the substrate the spray deposition systemheats the substrate using multiple radiant heaters 120. As shown in FIG.23, the radiant heaters may be disposed on one or both sides of asubstrate 101 such that they radiate heat towards the substrate so thatthe substrate is effectively heated as first particles 200 are depositedon the substrate from sprayers 104.

FIG. 24 is a side schematic representation of yet another embodiment ofa spray deposition system 100 during a material deposition process Likethe embodiment of FIG. 23, the spray deposition system of FIG. 24employs a radiant heater which radiates heat to a substrate 101 as firstparticles 200 are deposited on the substrate. In contrast to theembodiment of FIG. 23, the radiant heat is directed to a first side ofthe substrate and the first particles are deposited in a first materiallayer 202 on a second side opposite the first side. Such an arrangementmay promote even consistent heating of the substrate within a targetregion as compared to heaters that heat a substrate prior to being movedto be within a target region.

It should be understood that aspects of the various embodimentsdescribed herein may be combined or substituted. Further, the exemplaryembodiments of spray deposition systems disclosed herein may depositsingle layers or material layers onto a single side of a substrate ortwo opposing sides of a substrate. Additionally, the disclosed spraydeposition systems may deposit material layers on a substrate as part ofa non-continuous, semi-continuous, or continuous process. The disclosedspray deposition systems may also employ actuators which move individualmasks into or out of contact with a substrate or combined actuatorswhich move multiple masks simultaneously. Finally, the disclosed spraydeposition systems may deposit multiple material layers in sequenceeither at a single station at different times and/or at distinctphysically separated deposition systems as the disclosure is not solimited.

While the present teachings have been described in conjunction withvarious embodiments and examples, it is not intended that the presentteachings be limited to such embodiments or examples. On the contrary,the present teachings encompass various alternatives, modifications, andequivalents, as will be appreciated by those of skill in the art.Accordingly, the foregoing description and drawings are by way ofexample only.

What is claimed is:
 1. A system for forming a particle layer comprising:at least one sprayer configured to spray particles towards a substrate,the particles comprising at least one selected from the group of anelectrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material; a first maskmovable to selectively mask the substrate from the particles in a firstregion of the substrate; a second mask movable to selectively mask thesubstrate from the particles in a second region of the substrate,wherein the at least one sprayer directs the spray of particles towardsa portion of the substrate between the first mask and the second mask;and a heater configured to heat the substrate.
 2. The system of claim 1,wherein the first mask is a clamp actuated by an actuator, wherein theclamp is configured to selectively grasp the substrate.
 3. The system ofclaim 2, wherein the actuator is a pneumatic, hydraulic, or electricactuator.
 4. The system of claim 1, wherein the at least one sprayerincludes a first sprayer configured to spray particles toward a firstside of the substrate, and a second sprayer configured to sprayparticles toward a second side of the substrate opposite the first sideof the substrate.
 5. The system of claim 1, wherein the first mask is afirst electrode configured to electrically contact the substrate and thesecond mask is a second electrode configured to electrically contact thesubstrate, wherein the heater is configured to pass a current from thefirst mask to the second mask through the substrate to resistively heatthe substrate.
 6. The system of claim 1, further comprising a conveyorconfigured to move at least a portion of the substrate relative to theat least one sprayer.
 7. The system of claim 6, wherein the conveyorincludes a first roller and a second roller, wherein the first rollerand second roller are configured to move the substrate such that atleast a portion of the substrate moves from the first roller toward thesecond roller, wherein the substrate is unwound from the first rollerand wound onto the second roller.
 8. The system of claim 6, wherein theconveyor is configured to move the substrate relative to the at leastone sprayer while the particles are sprayed toward the substrate, andwherein the first mask and the second mask move in sync with thesubstrate.
 9. The system of claim 1, further comprising the substrate,wherein the substrate is a metal foil.
 10. The system of claim 1,wherein the particles further comprise a binder.
 11. The system of claim1, wherein the at least one sprayer includes a first sprayer and asecond sprayer, wherein the first sprayer is configured to spray firstparticles toward the substrate to form a first layer disposed on thesubstrate, and wherein the second sprayer is configured to spray secondparticles toward the substrate to form a second layer disposed on thefirst layer.
 12. A method for depositing material layers, the methodcomprising: masking a first region of a substrate; masking a secondregion of the substrate; heating the substrate; and spraying firstparticles comprising at least one selected from the group of anelectrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material towards theheated substrate to form a first layer on the substrate.
 13. The methodof claim 12, wherein spraying the first particles towards the heatedsubstrate includes spraying the first particles towards a first side ofthe substrate and a second side of the substrate opposite the firstside.
 14. The method of claim 12, wherein heating the substrate includespassing a current through the substrate via a first mask contacting thesubstrate and a second mask contacting the substrate to resistively heatthe substrate.
 15. The method of claim 12, wherein masking the firstregion of the substrate includes grasping the substrate with a firstclamp, and masking the second region of the substrate includes graspingthe substrate with a second clamp.
 16. The method of claim 15, furthercomprising moving the substrate relative to the first and second clamps.17. The method of claim 16, further comprising moving the substratewhile the first particles are sprayed towards the heated substrate. 18.The method of claim 12, further comprising calendering the first layer.19. The method of claim 12, wherein the first particles further comprisea binder.
 20. The method of claim 12, further comprising spraying secondparticles onto the first layer to form a second layer disposed on thefirst layer.
 21. A method of forming an electrode comprising: masking afirst region of a substrate to inhibit material deposition on thesubstrate in the first region; masking a second region of the substrateto inhibit material deposition in the second region; applying firstparticles comprising at least one selected from the group of anelectrochemical material, an ionically conductive material, anelectrically conductive material, and a separator material to thesubstrate to form a first layer; and applying second particlescomprising at least one selected from the group of the electrochemicalmaterial, the ionically conductive material, the electrically conductivematerial, and the separator material to the first layer to form a secondlayer disposed on the first layer.
 22. The method of claim 21, whereinapplying the first particles and the second particles includes sprayingthe first particles towards the substrate and spraying the secondparticles towards the first layer.
 23. The method of claim 21, whereinthe first particles include the electrochemical material and the secondparticles include the separator and/or the ionically conductivematerial.
 24. The method of claim 21, further comprising sequentiallycalendering the first layer and the second layer.
 25. The method ofclaim 21, further comprising calendering the first layer and the secondlayer simultaneously.
 26. The method of claim 21, further comprisingheating the substrate.
 27. The method of claim 26, wherein heating thesubstrate includes passing a current through the substrate via a firstmask contacting the substrate and a second mask contacting the substrateto resistively heat the substrate.
 28. The method of claim 21, whereinmasking the first region of the substrate includes grasping the firstregion of the substrate with a first clamp, and masking the secondregion of the substrate includes grasping the second region of thesubstrate with a second clamp.